The present invention relates to a method and apparatus for servicing a pressurized system, in particular an air conditioning or refrigeration system.
Servicing couplings are commonly employed to facilitate charging and evacuation of a pressurized fluid system, such as a refrigeration system, an air conditioning system, or a hydraulic system. The service coupling connects to a service port of the system. The service coupling opens a service port of a system, allowing fluids, including liquids or gases, to be exchanged with the system. A quick-release interconnection between the service port and the service adapter can facilitate the servicing process. For example, when servicing a refrigeration or air conditioning system the service coupling can be connected by a flexible hose to a refrigerant supply source, such as a pressurized bottle or cylinder. When the service coupling and service port is opened, refrigerant can flow through the coupling and into the refrigeration system. Because pressurized fluid systems can be serviced when the system is installed in a confined space such as a vehicle, service couplings having small dimensions can be useful for convenient servicing.
In order to maintain the performance of a pressurized fluid system, it can be important to keep air out of the system. In air conditioning systems, for example, system performance can deteriorate when air is in the system. In addition, introduction of air can also lead to introduction of moisture and other contaminants into the system. Thus, keeping air out of the system can be important when servicing a system.
The invention features a purge fitting for venting a pressurized system. Venting can release a gas, such as air, from the system. The pressurized system can be a climate control system (e.g., an air conditioning or refrigeration system), a brake system, a hydraulic system, or a service device for servicing a climate control system. The purge fitting allows air that may be trapped in the pressurized system to be vented by depressing a purge actuator, such as a purge button attached to the fitting. The air can be vented from an opening adjacent to the actuator or other orifice. By purging air directly from the system, the amount of air introduced into the system during servicing can be minimized. The service device can be a coupling member or a service unit. The invention also features a coupling member that can be compact in size. The coupling member can include a self-sealing valve assembly that prevents opening the coupling member until a proper coupling interconnection with a system to be serviced has taken place. The purge fitting can be incorporated in the coupling member or other service device.
In one aspect, the invention features a coupling member. The coupling member includes a body having a first end engageable with a first valve, a second end having a moveable control member, an inner surface defining an interior chamber, and a port in fluid communication with the interior chamber. The first valve can be a service port. The coupling member also includes a pusher disposed in the interior chamber and in contact with the control member. The pusher has a valve actuation portion extending toward the first end of the body. The pusher is movable by the control member from a valve closed position to a valve open position. The coupling member also includes a pin depressor proximate to the port having a first position oriented closer to the interior chamber relative to a second position which is closer to the port. The pin depressor moves from the first position to the second position when the first valve is engaged with the first of the body and the pusher is moved from the valve closed position to the valve open position. The pin depressor is in the first position when the first en of the body is not engaged with the first valve and the pusher is moved from the valve closed position to the valve open position.
The pusher can be engaged with threads to the control member. The pusher can move from the valve closed position to the valve open position by rotating the control member by less than one revolution. The second end of the body can include a groove. The control member can be moveably attached to the groove. Attachment can be made by a pin assembly, a set screw, or a snap ring.
The coupling member can also include a valve detection member movably disposed on the valve actuation portion. The valve detection member can be rotatably or slidably disposed on the valve actuation portion. The valve detection member moves relative to the valve actuation portion when the first valve is engaged with the first end of the body and the pusher is moved from the valve closed position to the valve open portion. The valve detection member is substantially stationary relative to the valve actuation portion when the first end of the body is not engaged with the first valve. The pin depressor moves from the first position to the second position when the valve detection member moves relative to the valve actuation portion.
The coupling member can include a second valve positioned within the port. The second valve is opened when the pin depressor moves from the first position to the second position. The first end can be engageable with a high pressure side refrigerant port or a low pressure side refrigerant port.
In preferred embodiments, the pin depressor is movably attached to the pusher.
In other preferred embodiments, the first end of the body includes a release sleeve assembly including an adapter connected to the first end of the body, a release sleeve over the adapter, and a spring between the release sleeve and the adapter. The adapter can be connected by threads, pins, one or more set screws, a snap ring, brazing, or soldering. The release sleeve assembly can include a plurality of balls distributed between the adapter and the sleeve. The balls are engageable with the first valve. The plurality of balls can include more than six balls (e.g., eight balls).
In other preferred embodiments, the coupling member includes a purge actuator exterior to the body. The purge actuator has a shaft extending through the interior chamber to the port. The shaft is capable of moving the pin depressor from the first position to the second position while in the valve closed position. In certain embodiments, the pusher can include a stop that prevents the shaft from moving the pin depressor when in the valve open position.
The purge actuator can include a button, a switch, a lever, a knob, or a rocker.
In preferred embodiments, the coupling member has an end-to-end dimension T that is unchanged in the valve open position and in the valve closed position.
In another aspect, the invention features a coupling member including a first end engageable with a service port, a valve within the coupling member, and a purge actuator capable of opening the valve. The coupling member can also include a service port detection member movably disposed within the coupling member. The service port detection member opens the valve when the service port is engaged with the first end. The port detection member does not open the valve when the first end is not engaged with the service port. The coupling member can be a release sleeve assembly at the first end including an adapter connected to the first end, a release sleeve over the adapter, and a spring between the release sleeve and the adapter.
In another aspect, the invention features a purge fitting. The purge fitting includes a body having a fluid inlet, a fluid outlet, and a vent port. The purge fitting also can include a purge actuator exterior to the body. The purge actuator has an open position and a closed position. The purge actuator seals the vent port when the actuator is in the closed position. The seal is broken and the vent port is opened when the purge actuator is in the open position. The fluid inlet and the fluid outlet are in fluid communication when the purge actuator is in the closed position, and the vent port, the fluid inlet and the fluid outlet are in fluid communication when the purge actuator is in the open position. Flow between the fluid inlet and the fluid outlet is substantially unrestricted when the purge actuator is in the open position and the closed position.
The purge actuator can include a shaft extending into the body to a shaft retaining member. The purge actuator can have a diameter that covers the vent port without blocking fluid flow. The body of the purge fitting can be a portion of a coupling member, a portion of a hydraulic system, a brake system, or a portion of a climate control system service unit. The service unit can be a service manifold, a valve core removal tool, a refrigerant cylinder, a fluid charge line, such as a hose, a refrigerant identifier or analyzer, a diagnosis instrument, a dye injector, a recovery and recycle station, or other device that can connect to a service port of a system.
In yet another aspect, the invention features a method of servicing a pressurized fluid system. The method includes attaching a coupling member to a service port of the system, the coupling member being connected to a service unit and including a safety valve, and opening the service port with the coupling member. The safety valve is opened by a valve detection member in the coupling member approximately when the service port is opened. The coupling member or the service unit can include a purge actuator. The purge actuator or coupling member can be manually activated or automatically activated by, for example, a control circuit. The method can include activating the purge actuator to vent air from the service unit prior to attaching the coupling member to the service port or prior to opening the service port. The service port can be a high pressure side refrigerant port or a low pressure side refrigerant port.
In yet another embodiment, the invention features a method of venting a pressurized system including moving a purge actuator from a closed position to an open position. The purge actuator can be a portion of a purge fitting or a portion of a coupling member. The pressurized system can be a service device or a climate control system. The climate control system can be an air conditioning system or a refrigeration system.
The method and apparatus of the invention can assist in the servicing of pressurized systems, such as air conditioning or refrigeration systems. The coupling member includes a self-sealing mechanism that can prevent or reduce refrigerant loss and injury in the event the coupler is accidentally disconnected under pressure. In addition, the coupling member can be constructed so that the control knob opens and closes the service port of the system in less than a complete revolution (i.e., in one half to two thirds of a complete revolution). The coupling member has a short length and small diameter, which can facilitate access to the service port in tight spaces. In addition, the coupling member can engage with the service port of the system using a release sleeve assembly including more than six steel balls (e.g., eight balls). Six or more balls increase stability and grip of the member with the valve. The coupling member can have a length (T) of about 1.6 inches that remains unchanged when the coupling is in the open and closed positions, and a diameter of about 1.1 inches. These dimensions can allow the coupling to mate with service ports in confined locations. The coupling member can be adapted to mate with Society of Automotive Engineers (SAE)-dimensioned ports and can be constructed from metal, such as, for example, brass, steel, stainless steel, or aluminum, for durability.
The method and apparatus of the invention can also include a purge feature that can facilitate servicing pressurized systems. The purge feature can be a purge fitting attached to a service device or a purge actuator incorporated into a device such as a coupling member. The purge feature can reduce or eliminate problems related to introducing air into pressurized fluid systems. The purge feature allows air to be vented in a relatively controlled manner while protecting the user from exposure to the fluid in the system. For example, a purge fitting can be attached to a recovery and recycle machine, a refrigerant cylinder, or a manifold gauge set, or a portion thereof. The purge fitting can attach to a standard hose fitting. The purge fitting can be constructed from metal, a plastic, or a composite. The purge feature can allow air to be vented from hoses and other parts of a service device prior to working on the system. The purge feature can prevent air from entering the system. Air can be vented from an air conditioning system service device during servicing by depressing the purge actuator. At the first sound or sign of refrigerant near the purge vent, the purge actuator can be released, stopping flow of the refrigerant nearly instantaneously. The purge feature can improve the safety of servicing a pressurized system. For example, the purge can help prevent or reduce release of fluids (e.g., liquids or gases), such as refrigerants, from the system or service device. In addition the purge feature can be configured to help protect the user from refrigerant freeze and reduce the duration of servicing.
Additional features and advantages of the invention will become apparent from the detailed description of the invention.